Synthetic resin and process of making same



- ing organic, substances that they take up and Patented Liay 1938 UNITED STATES V 2,118,482 srn'rnn'ncansm Ann raocsss or MAK- mo SAME Theodor Sutter, Basel, Switzerland, assignor to Cilia Products Corporation, Dover, Del., a corporation No Drawing. Original application June 30, 1931,

This invention relates tosynthetic resins from primary aromatic amines and aldehydes. 1 It comprises the process for the manufacture of these resins, the new products themselves, as well as the application of same in the industry of synthetic resins.

In Patent 2,002,601 and in the copending specifications Serial No.- 398,267, filedOctober' 8, 1929, and No. 400,154, filed October 16, 1929, there are described various substances which when added to condensation products .made in the presence of a mineral acid from primary aromatic amines and formaldehyde compounds profoundly vary the properties of these products, for instance their fluidity. durability, solidity at raised temperature and'the like. As such additional substances there are named in' the said specifications hardening agents consisting of aldehydic compounds, such as aldehydes, substances which yield aldehyde, aldehyde condensation products capable of being o.

hardened; also fiuinng agents,'-,such as fusible aldehyde condensation products and others.

According to the said specifications, the finished acid-free, dried and comminuted amine-form-- aldehyde-resin is incorporated with the added substance by mixing them together or by spraying or some similar operation.

It has been found on further investigation that i the most complete homogeneity possible of the mixture is of the greatest importance for the production .of the best possible properties in the final product. By intermixture in a dry condition complete homogeneity can only be attained with a considerable expenditure of time. Moreover, many of the additional substances available are viscous, syrupy or smeary masses which can be distributed uniformly in a substratum only with difiiculty. When it is sought to overcome this objection by using solvents, the mixture must be afterwards freed from the'solvent, which necessitates a further operation and loss.

It has now been found that very valuable products are obtained by adding an aldehydic compound to the condensation product resulting from the reaction of the primary aromatic amine and the formaldehyde compound in presence of the mineral acid at a stage priorto the drying of the resinous material.

- The present invention is based on the observation that the freshly precipitated amine resins made from aromatic amines and formaldehyde, probably in consequence of their extraordinarily large surface, have so high a capacity for adsorbflrmly retain components of such substances siderable losses of such substances'occur. In consequence of this property it is possible that many additional substances, such as aldehydes and any'kind of aldehyde condensation products, which may act merely as fluxing agents, or may develop ahardening action'on theresins, may be combineddirectly in aqueous solution with the amine-formaldehyderesins thereby to obtain not only a'particularly uniform distribution but also to avoid the isolation of the additional substance which is frequently tedious and costly, for even oily and syrupy substances are uniformly precipitated by adsorption on the voluminous formaldehyde resins, there being obtained preci'pitates that are easily filtered, washed, dried and pulverized.

The process of the invention is particularly valuable for fixing the resins homogeneously on and in substrata; such as paper pulp, wood-meal, asbestine, paper, textile fabrics or the like. The

more freely flowing products obtainable by this invention permit a more complete penetration of the substratum and the application" of lower pressures. a

The introduction of the additional substances hereinbefore named may occur at any stage of the manufacture of the amine-formaldehyderesin. Slowly reacting aldehydic compounds,

PATENTTI-OFIFICE such as furfural or benzaldehyde, as well as aldehyde condensation products may be dispersed even in an acid condensation solution, in which. case, when the resin is separated they are simultaneously thrown down. Additional substances soluble in bases, such as phenol alcohols or phenol resins, may be dissolved in the base serving for eliminating the acid and in this'manner precipitated together with the resin. (By the term phenol alcohols the products resulting from the ence of cold aqueous alkali are understood. They are also known as methylol-phenols," methylolcresols etc.). It is also practicable to stir or reaction of formaldehyde upon phenols in presthe additional substance, which for this purpose may be dissolved in a solvent miscible with water, I or the said suspension may be mixed "with an alkaline solution of a phenol-aldehyde condensafrom acid, if necessary after previous heatin'gt'o 1 v I facilitate filtration, is filtered, washed free from electrolytes and dried.

The molding powders may be molded in the usual way by application of heat and pressure.

,In certain cases they flow so easily and have such a high stability at moderate temperatures Example 1 93'parts of phenol are dissolved in 200 parts of caustic soda solution of 20 per cent. strength, 200 parts of formaldehyde of 38 per cent. strength are added in the cold and the whole is allowed to stand for some days. The solution then contains a mixture of phenol-polyalcohols.

As another operation 380 parts of aniline are dissolved in 500 parts of concentrated hydrochloric acid and the solution is diluted and stirred with 300 parts of formaldehyde of 38 per cent. strength for 1 hour at C. Then into the mixture thus obtained there is run, while stirring well, the above phenol-alcohol solution which is taken up without turbidity; the whole is poured into so much dilute caustic soda solution that the magma produced becomes only feebly acid. The whole is now made alkaline with sodium carbonate, filtered and the solid matter washed. The light colored powder thus obtained shows extraordinarily good fluxing and hardens at temperatures above 140 C. to pressed bodies of remarkable mechanical and chemical-resistance.

Emample 2 A solution of cresol-polyalcohols (dior tri methylol cresols) is obtained in manner analogous to that described in Example 1 by substituting 108 parts of crude cresol for the phenol.

a cent. strength and 300 parts of formaldehyde solution of 38 per cent. strength. The amineformaldehyde-resin and the cresol-polyalcohols are precipitated together. The solution must at the end be alkaline with sodium carbonate. The resin is filtered, washed and dried, and ground with parts of furfural. By pressing the product, bodies of very good properties are obtained.

Example 3 An acid condensation solution made from 93 parts of aniline, 80 parts of concentrated hydrochloric acid, 1000 parts of water and parts of the formaldehyde solution of 38 per cent. strength is allowed to flow into a strongly alkaline solution of phenol alcohols made by condensation of phenol with 1 moi. of formaldehyde in dilute alkaline solution and containing 25 parts of phenol-alcohol. The united solu tions are made feebly alkaline with sodium carbonate and the precipitate thus obtained is filtered, washed and. dried. The product can be pressed at 150 C. to bodies which are completely homogeneous.

. Example 4 104 parts of anhydroformaldehydeaniline are stirred in 200 parts of warm water and 300 parts" of hydrochloric acid of 12 per cent. strength are added. This mixture is stirred at 60-90 C. until everything is dissolved and, while still stirring, 15 parts of furfural are added. Then the whole is rim into a solution of phenol-polyalcbhols made by allowing to stand for several days 15 parts of phenol with 2 equivalents of formaldehyde in a dilute alkaline solution, this solution of phenol-polyalcohols having been first mixed with sumcient sodium carbonate to neutralize the acid in the amine-resin solution. ,A voluminous precipitate is produced which is filtered, washed and dried; the powder flows very well under pressure to produce compressed bodies.

Example 5 108 parts of cresylic acid are dissolved in 200 parts of caustic soda solution of 20 per cent. strength, 280 parts of a formaldehyde solution of 38 per cent. strength are added in the cold and the whole is allowed to stand for some days. Then 40 parts of formaldehyde of the same strength are added and the mixture is run, while stirring well, into a solution of 186 parts of aniline in 3000 parts of hydrochloric acid of 3.6 per cent. strength at a temperature of 40 C. After stirring well during one hour at.40 C., the mass is neutralized by addition of carbonate of sodium, filtered and the solid matter washed. By pressing the powder at a temperature above (3., bodies of very good properties are obtained.

The term primary aromatic amine", as employed in this application, is intended to cover not only true primary aromatic amines, such as aniline and its homologues, but also such derivatives thereof which under the conditions of the condensation described herein, also act like the true primary aromatic amines under the conditions of the present process to yield the same resins, for example, anhydroformaldehydeaniline, formylaniline or the homologues of those compounds, and the like.

The expression formaldehyde yielding compounds as employed herein, is intended to cover not only formaldehyde itself, but its polymers -or any other substances splitting off formaldehyde or capable of forming methylene links un-- der the conditions of the condensation, as it has been found that such substances or polymers may also be used in place of formaldehyde itself.

The term synthetic resinous material',, as used in this specification and claims, is intended to cover not only the pure resin, but all forms in mary aromatic amine with at most an equimolecular proportion of 2. formaldehyde yielding compound in the presence of a mineral acid and subsequently precipitating the product by an agent of alkaline character, which comprises adding a phenolpolyalcohol to the condensation product resulting from the reaction of the primary aromatic amine and the formaldehyde yielding compound in the presence of the mineral acid at a stage prior to the drying of the resinous material,

whereby the said phenolpolyalcohol is homogeneously adsorbed by said amine condensatio product.

2. The step in the process of manufacturing synthetic resins from amine-formaldehyde condensation products obtained by reacting aniline with at most an equimolecular proportion of a formaldehyde yielding compound in the presence of a mineral acid and subsequently precipitating the product by an agent of alkaline character, which comprises adding a phenolpolyalcohol to the condensation product resulting from the reaction of the aniline and the formaldehyde yielding compound in the presence of the mineral acid at a stage prior to the drying of the resinous material, whereby the said phenolpolyalcohol is homogeneously adsorbed by said amine condensation product.

3. The step in the process of manufacturing,

synthetic resins from amine-formaldehyde condensation products obtained by reacting a primary aromatic amine with at most an equimolecular proportion of a formaldehyde yielding compound in the presence of a mineral acid and subsequently precipitating the product by an agent of alkaline character, which comprises adding phenol-polyalcohols to the condensation product resulting from the reaction of the primary aromatic amine and the formaldehyde yielding com pound in the presence of the mineral acid at a stage prior to the drying of the resinous material, whereby the said phenol alcohols are homogeneously adsorbed by said amine condensation prod- 1 mary aromatic amine and at most an equimolecuct.

4. The step in the process of manufacturing synthetic resins from amine-formaldehyde condensation products obtained by reacting aniline with at most an equimolecular proportion of a formaldehyde yielding compound in the presence of a mineral acid and subsequently precipitating the product by an agent of alkaline character, which comprises adding cresol-polymethylol to the condensation product resulting from the reaction of the aniline and the formaldehyde yielding compound in the presence of the mineral acid at a stage prior to the drying of the resinous material, whereby the said cresol-polymethylol are homogeneously adsorbed by said amine condensation product.

5. The process of manufacturing synthetic resinous material which comprises reacting a priular proportion of a formaldehyde yielding compound in the presence of a mineral acid to form a condensation product, adding phenol polyalcohols to the acid solution of the condensation. product, and thereafter-treating the solution with an agent of alkaline character which causes the precipitation of the condensation product and product, whereby homogeneous admixture therethe phenol polyalcohols, whereby the said phenol polyalcohols are homogeneously adsorbed by said amine condensation product.

6. The process of manufacturing synthetic resinous material which-comprises reacting aniline and at most an equimolecular proportion of a formaldehyde yielding compound in the presence of a mineral acid to form a condensation product, adding phenol polyalcohols to the acid solution of the condensation product, and thereafter treating the solution with an agent of alkaline character which causes the precipitation of the condensation product and the phenol poly alcohols, whereby the said phenol polyalcohols are homogeneously adsorbed by said amine condensation product.

7. The process of manufacturing synthetic resinous material which comprises reacting a primary aromatic amine and at most an equimolecular proportion of a formaldehyde yielding compound in the presence of a mineral acid to form a condensation product, treating the solution with an agent of alkaline character and adding a phenol polyalcohol to thesuspension of the precipitated condensation product, said phenol polyalcohol being capable of adsorption by said amine condensation product, whereby homogeneous admixture thereof is assured.

8. The process of manufacturing synthetic resinous material which comprises reacting aniline and at most an equimolecular proportion of a formaldehyde yielding compound in the presence of a mineral acid to form a condensation product, treating the solution with an agent of alkaline character and adding a phenol polyalcohol to the suspension of the precipitated condensation product, said phenol polyalcohol being capa-- ble of adsorption by said amine condensation of is assured.

9. The step in the process of manufacturing synthetic resins from amine-formaldehyde condensation productsobtained by reacting a primary aromatic amine with at most an equimolecular proportion of a formaldehyde yielding compound in the presence of a mineral acid and subsequently precipitating the product by an agent phenol polyalcohol to the condensation product resulting from the reaction of the primary aromatic amine and the formaldehyde yielding compound in the presence of mineral acid, and in of alkaline character, whichcomprises adding a substantial absence of unreacted amine, at a uct.

THEODOR BUTTER. 

